Wind conduction for labial pipes of organs



Nov. 5, 1940. scHuLzE WIND CONDUCTION FOR LABIAL PIPES OF ORGANS Filed Jan. 20, 1938 Anni I'm/en for:

' the tone of the organ pipe.

Patented Nov. 5, 1940 UNITED STATES PATENT OFFICE Herbert Schulze, Berlin-Spandau, Germany Application January 20, 1938, Serial No, 185,952 In Germany December 24, 1936 1 Claim.

The present invention relates to pipe organs and particularly pertains to the construction of the pipes and the labial passages thereto.

The foot-board, serving as a rest for the pipe and also containing the wind-conduction or wind-trunk, has been in the prior constructions provided at the outlet of the wind-trunk with a pot-shaped widening, into which the mouth of the pipe is placed. For this purpose, this mouth was given the shape of a cup at its resting place, whereby the hole of the mouth is reduced to a diameter which is smaller than that of the windtrunk in the foot-board. This usual construction takes into consideration that a wind-tight connection between the mouth of the pipe and the foot-board is required, accounting for any changes in the shape of the wood, and in addition, that it is necessary to prevent the lower portion of the mouth from being deformed in the case of vertical mechanical stresses. These mechanical stresses may be rather great and are caused by the weight of the pipe and by knocks and pressures in tuning. In order, therefore, to avoid a deforming wedge-action upon the mouth (especially in the case of heavy pipes) the angle formed by the resting surface with the vertical direction of the pressure of the pipe must not be too acute but should be as nearly at right angles as will permit to fix the position of the pipe in the foot-board and to ensure a wind-tight iiting.

Based on numerous experiments, it has been found that the shape of the mouth of the pipe and the manner in which it is arranged on the foot-board have a considerable influence upon Hitherto, the importance of the shape of the mouth and the influence of the passage between the wind-trunk in the foot-board and the mouth of the pipe upon the tone of the organ pipe was neither recognised nor considered.

An important characteristic for the tone of an organ pipe is, apart from the frequency composition of the stationary tone, the formation of the tone and its frequency composition. The quicker the tone is formed, or the shorter the period is between the opening of the pipe-valve and the arising of the stationary tone, the better is the ability of the pipe to act on rapid air impulses. It has been found that this act of forming the tone depends in a considerable degree on the wind-conduction between the Wind-chest and the wind-trunk in the foot-board. For example, it has been ascertained that the period of the toneformation, when using a composition-chamber,

or when the path of the wind is angled many times, takes much longer than when a tonechamber with the freest possible wind-path is used. Therefore, the tone arises much clearer with a tone-chamber than with a composition- 5 chamber.

Although the mentioned differences in the various chambers have been ascertained, it was not recognised that the wind-conduction just before and also inside the mouth of the pipe is of considerable influence upon the tone of a pipe, the arising of the tone, and the easy response of the pipe. Thus, with the described shaping and placing of the pipe, no clear arising tone can be attained, as the period of the tone-formation is relatively long and the pipe does not respond easily. Furtheremore, a relatively high wind-pressure is necessary in the case of these known forms of pipes, which is the cause of noises and has an unfavourable influence upon the tone.

These faults have been removed in carrying out the invention by a wind-conduction for labial pipes of organs in which the mouth of the pipe and the wind-trunk in the foot-board are shaped in such a way that, in order to avoid the formation of whirls, these two parts lead into one another without sudden changes of the cross section, and that a wind-chest is used which ensures a uniform, nearly laminary flow of wind into the mouth of the pipe.

According to the invention, the mouth of the pipe is advantageously formed in straight lines, conical or cylindrical, and all windtrunks in the foot-board are so dimensioned that the diameter of the hole in the mouth of the pipe is equal to the diameter of the wind-trunk in the footboard where it leads into the mouth.

The nature of the invention will be apparent from the following description with the aid of the accompanying drawing, in which:

Figs. 1 to 5 are sectional views illustrating various embodiments of the pipe mouths and wind trunks in the foot board.

Fig. 6 is a sectional View of a portion of a conical shaped wind chest.

Fig. 7 is an enlarged sectional view illustrating details of the apparatus shown in Fig. 6.

Fig. 8 is a top plan view of means for securing an organ pipe to the foot board.

In carrying out the invention all shapes of pipemouths as well as the manner of mounting, avoid projecting edges or dead angles, and therefore the air-current is not disturbed or impaired in any way.

Thus, Fig. 1 shows a slightly conical pipemouth Hi, the lower portion ll of which is placed in a widening l8 of the wind-trunk IS in the foot-board corresponding with the pipe-mouth, the diameter of the hole in the pipe-mouth being equal to that of the wind-trunk at the passage. Therefore, the recess 20 in the wind-trunk corresponds with the wall-thickness a of the pipemouth.

With larger pipes or with cylindrical pipemouths, this mounting is rather diiiicult, as the weight of the pipe or the strokes applied in tuning cannot be borne by the conical resting surface of the widening i8 alone. For this purpose, the constructions according to Figs. 2 to include bearing-rings 2| to 24 made of metal which are fixed to the pipe-mouth near its end, for example soldering or welding. These bearing-rings serve to effectively support the pipe on the foot-board 5. In the construction according to Figs. 2, 3 and 5 the bottom 25 of the bearing-ring is curved and fits exactly into a corresponding pot-shaped groove 26 in the footboard. The pot-shaped groove 26 can suitably be burnt into the foot-board. These bearing-rings bear the whole weight of the pipe so that there is no danger of displacing the pipe-mouth or of altering its shape.

The mounting of the pipes according to the invention may also be applied to existing organs with the known pot-shaped grooves 4 in the foot-board as shown in Fig. 4. In this case, the bearing-ring 23 lies on the edge surface 21 of the pot. This ring has a listening hole 28 in order to ascertain whether the pipe is in wind-tight connection at the resting place 29 on the wind-trunk of the foot-board. As will be seen, the pipe-mouth is set into the foot-board at its resting place 29 to ensure wind-tight fitting. The mounting according to Fig. 4 is especially adaptable to large pipes.

A particularly appropriate construction is shown in Fig. 5, in which a conical pipe-mouth 30 is provided. It will be seen that the portion of the wind-trunk below the recess 3| is conical, as indicated by the dotted lines 32. This shaping is to enable the wind-trunk 33 to be widened or to be bored open if more wind should be required. In the known type, when more wind was required, the hole in the pipe-mouth was simply widened, which is not possible with the new construction. Appropriately, the passage between the cylindrical boring 33 and the cone 32 is rounded off, as shown in Fig. 5. In order to avoid any disturbance of the wind, the edges 34% at the entrance of the boring 33 in the footboard are also rounded ofi. A sound-board 44 with the slide 45 are also shown in Fig. 5.

The efiect intended by the invention depends not only upon a smooth passage between the wind-trunk and the pipe-mouth in order to avoid any disturbance of the wind, but also upon the application of a special wind-chest in order to provide a uniform and approximately laminary wind-current before the entrance to the pipemouth. The mentioned purpose is suited especially by using a sound-board, in which the adturbulent currents, arising in such types of windchests, into laminary currents before entering the pipe-mouth. Thus, for example, in using a wind-chest according to Fig. 6 with a conical valve 35, a rectifier 31, consisting, according to Fig. '7, of a number of parallel channels 38, is inserted in the wind-trunk 36. By passing these narrow parallel channels, the wind enters the pipe-mouth 39 in a laminary current.

A holding device for pipes with a bearing-ring where the diameter of the bearing-ring is larger than the diameter of the pipe is shown in Fig. 8. This device consists of a board 4!] with an opening 4!, above which are two smaller boards 42 and 43, the latter being removable and the former being fixed. After removing the board 43, the pipe can be inserted with the bearing-ring through the opening M and is secured by the board 43. I

Practical tests with the wind-conduction according touthe invention have led to very good results. The less resistance is offered to the wind at the pipe-mouth, the clearer is the rising tone of the pipe. Consequently, the organist has the feeling of accurate playing. The stationary sound has more colour and is more capable of mixing (synthesis). In addition, the volume of sound is very great, enabling to have less registers with the suggested construction. Furthermore, the wind-pressure may be lower than hitherto, owing to the freeness of the wind-path, without having to fear a weak sound of the organ. Low wind-pressure also improves the tone.

Despite the relatively low wind-pressure, the pipes respond easily.

The described forms of the pipe-mouth and the manner of attaching the pipes on the windchest do not only apply to wind-chests made of wood, but also to metal wind-chests in a corresponding sense.

I claim:

In a pipe organ the combination of, a foot board having an opening therein, a pipe fitting in said opening and having an inner diameter at the mouth thereof substantially equal to the opening in the foot-board so as to provide free communication between the opening and the pipe without any abrupt changes in cross-section, a sound-board providing a tone chamber which communicates with the pipe through a straight channel in the foot-board, and said channel being substantially rounded off at its entrance to the tone chamber.

HERBERT SCHULZE. 

